Ankle joint for artificial legs



Nov. 11, 1952 E. c. ELLERY 2,617,115

ANKLE JOINT FOR ARTIFICIAL LEGS Filed July' 25, 1949 FIG. l.1

FIG. 2.

FIG'. 3.

25 I8 25 I5; I7

FIG. 6.

l 7 WWII/4&4...

42 ATTORNEYS Patented Nov. 11, 1952 UN IT'ED f ).FFH3131` ANKLE .J 01N'l5 FOR ARTIFICIAL .LEGS

Emmen c. Euere; Hollywood; ea-1in Application Julyz, 194e. V Serial No..1.06.6911

(CL2 S+-6).,

4 Claims. 1

This invention has to do with articial legs'of a type embodying v.a feet,member pvetalyeennected .to a leg member for limited relative pivetelmovement..

While severaltypes of ankle joints have been devised for. .use inartificial legs, so far .as I am aware such. joints have beenunsatisfactory'in that when worn for any length of time they Causepressure sores to develop on the amputated stump of the wearer. Forexample, one form of joint which has been. widelyj used in artificiallegs makes use ofV pairA oirubberbumpers for limiting and resistingthepivo-talactionoffthefoot relative to` ,theleg.. Since considerable.forceis required to compress theiubber,.bumperelements to obtain pivotalmovement ofthe parts, pressure is brought to bear upon localized areas.of the stumpresulting insores which-can become quite painful. As .aresult, the wearerv of this type-of leg nds it extremely ydiiiicult toproperly manipulate the leg..

Another diiliculty with. conventionalf artificial legs is the fact thatthey .do not provide for automatically raising the forward portion-ofthe foot with the result that a wearer tends to stub the toe portion ofthe foot andvcannot swing the leg forwardly in `avertical plane withoutconstant danger of -falling. It is alsotrue of many -joints tha-.t onlyvery limited movement is possible at the ankle joint.

An object of this inventionfisto provide anovel and improVedankle-jjointstructure-for an artiiic-ialleg` =which does-I not have'. the.`aboveenoted disadvantages inherent inalegs; having `converttional` ankleVj oints A particular Object is to prov-ide aniankle joint which. does`not result in undue pressure being brought upon the stump-ofthe `wearerof-an artificial leg embodying fthe joint'. vwith the result that thev-eerer/.is entirely free .of lpressure sores and theleg may ,becomfortably. wor-n.

Anotherobjeetis `to providefan anklevjoi-nt :for anarticial leg. in.which means are vprovided .ior autmatieally raisingf-the toe or forwardportion. of. .the foot lof. Ythe. lappliance Fwhenq-the weight of thewearer is taken off the leg in normal walking thereby. greatlydiminishing the hazards. of walking., especially over uneven ground andupgrade.

A further .object of. the inventionistofprovide an ankle joint.means.whichl isv deeigned --to ,absorb the shock when .thelee contactsthe groundv -as the walking step begins.

Av still further object of the invention is.to provide an anklejointstructure permittinga,

relatively large pivotal movement embodying means for adjusting theamount of pivotal movement or excursionfof the joint.

Another object is to provide ankle joint means in whichv spring means isemployed `for automatically raising the 'toe of the foot and 'forabsorbing the shock-of the heel striking the ground.

Af-fur-therobject of the invention is t0 DIfovide asimple anklejoint--construction which may be economically manufactured and readilyinstalled in articial legs.

These and "otherobjects will be Yapparent from the drawing and thefollowing descrptionthereof;

Referring to the drawing, which is for illustrative purposes only:

Figs l *isi an elevational Iview partly broken away of an artificial legembodying the invention;

Fig. 2 `is aside elevational view of an ankle vjoint structureembodyingvthe invention;

Fig.l 3 'is a plan view of thestructure of Fig.Y 2;

Fig.l 4 isa sectional view onthe line i4-4 Yof Fig. 2

Fig. 5V-isa sectional lview onfthe line 5--5 of IFig'. 3; and

Fig. 6 is a cross section-on the line S- of Fig. 2.'

More particularly describing the invention, reference numeral I Igenerally indicates an arti- .cial leg-which includes a leg part I2 anda foot member III.. These parts vare pivotally connected for vlimited`relative pivotal movement by. means offanl ankle -joint structuregenerally indicated by .numeral 15."

The ankle joint structure I 5 comprises basically a pair of plates whichare hingedly or pivotallyv connected together vwith means -foradjustably limiting the pivotal 'movement -of lthe plates and a-meansfor biasing the plates in one direction. Referring particularly to"Figs,- 2-6,' the ankle joint-means includes an upper plate member I6and 'a.=lower plate I'I. The upper plate is provided With'anupwardly'extending centrally 1ocated boss I8 having `a threaded socketi9 for the .reception of afboltwhich is held in position bymeansvofae-retaining nut 2I. The bolt 20-is adapted toeXtend-.through anopening 23 formed in a mounting partition 24 (Fig. 1). at the lowerendor the-leg portion I2fof the. artificial leg. The plete I6 .is.alsosprovided withanpropriate .holes p25 ferr-the v`re,Cantierioffxneunting screws. and these-together.. with gafnut. 26 and a Washer21.0n the lbolt serveto-secure the Yupper.plate tothe leg.

Theaupper. plate.. is formed Eto. provideA` three depending centrallydisposed lugs or ears, the outer two of which have been indicated by thenumeral 30 and the innermost or centrally disposed one of which has beenindicated by numeral 3l. These parts of the upper plate are providedwith axially aligned bores 30', 3 I for receiving a pivot pin 32 whichwill be further described later.

The lower plate I'I is centrally apertured at 35 and is provided with apair of guide ribs 36 on its inner surface. A U-shaped connecting member38, including a base portion 39, adapted to t between the guide ribs 36,serves to mount the lower plate I'I and connect it to the upper plate.The connecting member is provided with a threaded bore 39' in the base39 which receives a mounting bolt 42, the mounting bolt being providedwith a shoulder 43 for abutting the outer surface of the lower plateI'I.

The connecting member 38 includes the two leg portions 45 which arebored at 45 to receive the pivot pin 32. Various means may be providedfor securing the mounting pin in place. However, in the form of theinvention shown, each of the outer lugs 30 of the upper plate arerecessed at 41 to receive retaining washers 4B. These washersaccommodate retaining screws 49 which thread into the ends of the pivotpin 32.

The mounting pin 42 is adapted to extend through a bore 52 in the body53 of the foot element I4 of the artiicial leg. In addition, the lowerplate is provided with screw holes 54 so that the plate may beadditionally anchored to the body 53 by screws (not shown).

It will be obvious from the description thus far that the constructiondescribed provides for pivotal movement of the plates I6 and I'!relative to each other. In order to limit this movement a pair ofadjustable stops; is provided. Re-

ferring particularly to Figs. 2 and 5, these stops are mounted on thelower plate one at each end thereof and each comprises an adjustmentscrew 56 which is threadedly received in the plate and which carries alock or retaining nut 51 thereon for locking the screw in adjustedposition. The inner ends of the screws are provided with a flatplate-like head 58 upon which is mounted a rubber or rubber-like bumper60. The bumpers are adapted to contact the inner surface of the upperplate I6 and for this purpose the heel or rearward end of that plate isprovided with a recess 6I on its inner surface for the reception of therear stop member.

It is a particular feature of the invention that means are provided inthe ankle joint for automatically cushioning the leg as the heelcontacts the ground during walking and for automatically raising the toeof the foot when weight is taken off the leg. The means foraccomplishing this comprises a compression spring 64 which is mountedrearwardly of the pivotal axis of the plates and is shown as carried ona pin 65 mounted on the lower plate. The upper end portion of the springis received within a suitable bore or recess 56 formed in the undersideof the upper plate I6.

It will be apparent that, with the construction described, the excursionor amount of relative pivotal movement between the upper and lowerplates and hence the foot I4 and leg I2 of the articial leg, may belimited and adjusted to suit a particular wearer by means of theadjustable stop or abutment means described. It will also be apparentthat the spring 54 serves as a means for cushioning the shock or jar ofthe leg contacting the ground and serves to automatically raise the toeor forward portion of the foot I4 during walking as the weight of thewearer is taken off the leg. It is, of course, contemplated that atension spring might be employed forwardly of the pivotal axis of theplates in place of the compression spring shown;

Although the invention has been particularly shown and described, it iscontemplated that various changes and modications can be made withoutdeparting from the scope thereof as defined in the claims.

I claim:

l. In ankle joint means for an artificial leg having a leg portion and afoot portion, an upper plate having an upwardly extending mounting boltfor securing the plate to the leg portion of the artificial leg, saidplate having apertured depending lugs centrally thereof, a lower plate,a pivot pin carried by the lugs on the upper plate, a connecting memberreceiving said pivot pin and pivotally connected to the upper platethereby, a mounting bolt detachably securing said lower plate to saidconnecting member and being adapted to secure said connecting member andlower plate as a unit to the foot portion of the artificial leg, aspring interposed between said plate for biasing the plates pivotally inone direction, and a pair of adjustable stops for limiting relativepivotal movement of the plates, said stops being located one at each endof said lower plate and each comprising a set screw carrying a resilientpad for engagement by the upper plate.

2. In ankle joint means for an artificial leg having a leg portion and afoot portion, an upper plate, said plate having apertured depending lugscentrally thereof, a lower plate, a pivot pin carried by the lugs on theupper plate, a connecting member receiving said pivot pin and pivotallyconnected to the upper plate thereby, a mounting bolt detachablysecuring said lower plate to said connecting member and being adapted tosecure said connecting member and lower plate as a unit to the footportion of the articial leg, and a pair of adjustable stops for limitingrelative pivotal movement of the plates, said stops beng located one ateach end of said lower plate and each comprising a set screw carrying aresilient pad for engagement by the upper plate.

3. In ankle joint means for an artificial leg having a leg portion and afoot portion, an upper plate, said plate having apertured depending lugscentrally thereof, a lower plate, a pivot pin carried by the lugs on theupper plate, a connecting member receiving said pivot pin and pivotallyconnected to the upper plate thereby, a mounting bolt detachablysecuring said lower plate to said connecting member and being adapted tosecure said connecting member and lower plate as a unit to the footportion of the artificial leg, and a spring interposed between saidplates for biasing the plates pivotally in one direction.

4. In ankle joint means for an artificial leg having a leg portion and afoot portion, an upper plate, said plate having apertured depending lugscentrally thereof, a lower plate, a pivot pin carried by the lugs on theupper plate, a connecting member receiving said pivot pin and pivotallyconnected to the upper plate thereby, a mounting bolt detachablysecuring said lower plate tc saidv connecting member and being adaptedto REFEREL CES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Number Name Date Foster June 29, 1869Loeiller July 1, 1902 Gaines et al Aug. 5, 1913 Beck July 9, 1940FOREIGN PATENTS Country Date Germany Mar. 27, 1923 Germany Sept. 29,1925

